The present invention relates to devices for closing packaged products. More particularly, this invention relates to improved devices for sealing casings filled with foodstuffs, especially meat products like bolognas, salamis, hams, etc., so as to substantially reduce or eliminate leakage resulting from improperly installed metal fasteners or clips placed at the terminal ends of the filled casings.
In the preparation of sausages, sausage paste or emulsion is formed of comminuted meat, together with fillers, seasonings, spices, etc., and is used to fill sausage casings. The sausage emulsion is introduced through a stuffing horn into the casing. In the case of small sausages, the casing which is filled with sausage emulsion is twisted, tied or clipped and thus formed into suitable links at predetermined intervals and subsequently processed. In the case of large sausages, such as bolognas, salamis, and the like, the sausage meat emulsion is introduced into a large, heavy-walled casing with the end closed, and is formed into a single large link or stick of sausage. The casing filled with the sausage meat may be subjected to cooking, smoking, etc., or in some cases, may be supplied to the customer without additional processing. Small sausages of the frankfurter, knockwurst or vienna type are generally smoked and cooked and the casing removed prior to marketing.
As previously indicated, in preparation of large diameter sausages a casing is first placed on a stuffing horn of an automatic meat stuffing apparatus, meat emulsion extruded through the horn and the ends of the casing are closed. Automatic meat stuffing apparatus used in such filling operations frequently employ tying or clip punch devices to form end closures on filled meat and sausage casings. Representative examples of automatic meat stuffing apparatus include those described in U.S. Pat. No. 3,919,739, such as the model FUT-70 by the Futaba Corporation. Other sausage machines utilizing clip punch devices are described in U.S. Pat. Nos. 3,553,768 and 3,237,290.
Typically, as part of the sausage packaging process a filled casing is clamped at each end by a shutter mechanism and metal clips or fasteners automatically banded to the terminal ends of the casing to form secure end closures. However, the banding process, in some instances, can result in puncturing or tearing the casing material by overforming the metal clips resulting in a loss of product, juices, etc. Likewise, underforming casing clips can also produce similar results whereby product is lost due to clips being applied too loosely. In many instances, such results can be attributed to the clip punch per se. That is, when such a device is even slightly out of adjustment defective banding of casings during meat filling operations can occur. Seemingly, minor differences in manufacture and wear on parts can cause clips to form differently from location to location. In addition, clip punch devices used in sealing filled meat casings have lacked convenient and dependable means for adjusting the length of stroke to compensate for variances, such as casing thicknesses and clip sizes. Consequently, too often the length of the downward stroke of the device is incorrect for a given application.
One example of a clip punch is described in U.S. Pat. No. 3,583,056. This particular punch has an adjustable down stroke, however, the length of the down stroke is controlled by a combination of an external shaft and a turning nut affixed to the top of a piston. The turning nut lacks a positive locking mechanism, and consequently, more frequent adjustments could be required. Accordingly, there is a need for an improved clip punch device which will provide a flexible and dependable means for adjusting the length of stroke of the device for variances in casing and clip sizes while avoiding overforming and underforming said clips during the banding process. In addition, once the length of stroke has been adjusted it should remain fixed and not be subject to loosening requiring further adjustments.